* Translated the chapter "introduction" into Ukrainian and added locale-strings.
* Small clean. Added all localizations for Ukrainian.
* Translation + Figure fixes
* Spell fix
* Resolved a conflict with "upstream/master": chose mine "locale-strings.js"
* "kz-AU" -> "uk-UA" for "Roboto" font
* Added a localization for "previous"/"next".
Co-authored-by: Pomax <pomax@nihongoresources.com>
